List of United States Supreme Court cases, volume 221

This is a list of cases reported in volume 221 of United States Reports, decided by the Supreme Court of the United States in 1911.

Justices of the Supreme Court at the time of volume 221 U.S.
The Supreme Court is established by Article III, Section 1 of the Constitution of the United States, which says: "The judicial Power of the United States, shall be vested in one supreme Court . . .". The size of the Court is not specified; the Constitution leaves it to Congress to set the number of justices. Under the Judiciary Act of 1789 Congress originally fixed the number of justices at six (one chief justice and five associate justices). Since 1789 Congress has varied the size of the Court from six to seven, nine, ten, and back to nine justices (always including one chief justice).

When the cases in volume 221 were decided the Court comprised the following nine members:

Standard Oil Co. v. United States and United States v. American Tobacco Co.
Standard Oil Co. v. United States, 221 U.S. 1 (1911), and United States v. American Tobacco Co., 221 U.S. 106 (1911), are a pair of major antitrust decisions by the Supreme Court. In Standard Oil the Court found the company guilty of monopolizing the petroleum industry through a series of abusive and anticompetitive actions. The decision resulted in the breakup of Standard Oil into 34 separate companies. (Many of these have since recombined, particularly into ExxonMobil. ) The Court in American Tobacco held the combination in that case was in restraint of trade and an attempt to monopolize the business of tobacco in interstate commerce within the prohibitions of the Sherman Antitrust Act of 1890. As a result, the American Tobacco Company was split into four competitors.

Citation style
Under the Judiciary Act of 1789 the federal court structure at the time comprised District Courts, which had general trial jurisdiction; Circuit Courts, which had mixed trial and appellate (from the US District Courts) jurisdiction; and the United States Supreme Court, which had appellate jurisdiction over the federal District and Circuit courts—and for certain issues over state courts. The Supreme Court also had limited original jurisdiction (i.e., in which cases could be filed directly with the Supreme Court without first having been heard by a lower federal or state court). There were one or more federal District Courts and/or Circuit Courts in each state, territory, or other geographical region.

The Judiciary Act of 1891 created the United States Courts of Appeals and reassigned the jurisdiction of most routine appeals from the district and circuit courts to these appellate courts. The Act created nine new courts that were originally known as the "United States Circuit Courts of Appeals." The new courts had jurisdiction over most appeals of lower court decisions. The Supreme Court could review either legal issues that a court of appeals certified or decisions of court of appeals by writ of certiorari.

Bluebook citation style is used for case names, citations, and jurisdictions.
 * "# Cir." = United States Court of Appeals
 * e.g., "3d Cir." = United States Court of Appeals for the Third Circuit
 * "C.C.D." = United States Circuit Court for the District of . ..
 * e.g.,"C.C.D.N.J." = United States Circuit Court for the District of New Jersey
 * "D." = United States District Court for the District of . ..
 * e.g.,"D. Mass." = United States District Court for the District of Massachusetts
 * "E." = Eastern; "M." = Middle; "N." = Northern; "S." = Southern; "W." = Western
 * e.g.,"C.C.S.D.N.Y." = United States Circuit Court for the Southern District of New York
 * e.g.,"M.D. Ala." = United States District Court for the Middle District of Alabama
 * "Ct. Cl." = United States Court of Claims
 * The abbreviation of a state's name alone indicates the highest appellate court in that state's judiciary at the time.
 * e.g.,"Pa." = Supreme Court of Pennsylvania
 * e.g.,"Me." = Supreme Judicial Court of Maine